Blog

Your Source for Automatic Drills, Multiple Spindle Heads, and more

Standard NPT Tap Drill Sizes Chart

StandardNPTTapDrillSizesChart.pdf

Standard NPT Tap Drill Sizes

NPT Size Tap Drill Size (in.) Decimal Equivalent (in.)
1/16 – 27 “C” 0.242
1/8 – 27 “Q” 0.332
1/4 – 18 7/16 0.438
3/8 – 18 9/16 0.562
1/2 – 14 45/64 0.703
3/4 – 14 29/32 0.906
1.0 – 11 – 1/2 1-9/64 1.141
1 – 1/4 – 11 – 1/2 1-31/64 1.484
1 – 1/2 – 11 – 1/2 1-23/32 1.719
2.0 – 11 – 1/2 2-3/16 2.188
2 – 1/2 – 8 2-39/64 2.609
3.0 – 8 3-15/64 3.234

1 Response to "Standard NPT Tap Drill Sizes Chart"

Machinist Family

July 9, 2014 at 10:35 pm

My spouse and I stumbled over here from a different page and thought I might check
things out. I like what I see so now i am following you.

Look forward to checking out your web page repeatedly.

Leave a Reply

Are You Human? *

What is 14 + 9 ?
Please leave these two fields as-is:
IMPORTANT! To control spam, please answer the math problem. AutoDrill Staff